1. Field of the Invention
The present invention generally relates to a transmission line, more particularly to a transmission line that adopts double-contact connectors to be as main transmission interfaces.
2. Description of the Related Art
With advances in technology, computer has become popular in our lives, and that to cope with the rapid development of computer peripheral electronic devices, the market also developed a variety of different types of connectors so as to connect with peripheral electronic devices with different transmission interfaces.
In general, the connector has a male connector and a female connector corresponding to the male connector, and a male connector cannot plug into a female connector that is not the same connecting interface with the male connector, and a certain direction shall be followed while a male connector and a female connector plug into each other. If the direction is wrong, the plug may not work.
For Universal Serial Bus (USB) connector, each of the male USB connector and the female USB connector both has a tongue portion therein. If plugged in a wrong direction, the tongue portion in the male USB connector and the tongue portion in the female USB connector may be against to each other. For general users, such design is a foolproof design, but for other users, the application is really not flexible and inconvenient.
Accordingly, the market proposes a double-plug female connector. The design of the double-plug female connector is to dispose the tongue portion thereof in the middle of the connector, so as to divide the connector into an upper accommodating area and a lower accommodating area and dispose connecting pins in an upper layer and a lower layer respectively. So, when the front surface of the male connector plugs into the female connector, the tongue portion of the male connector may insert into the upper accommodating area and electrically connect with the conducting pins of the upper accommodating area. In addition, when the rear surface of the male connector plugs into the female connector, the tongue portion of the male connector may insert into the lower accommodating area and electrically connect with the conducting pins of the lower accommodating area. Therefore, regardless of the male connector plugging into the female connector via the front surface or the rear surface, the plug can be made and the electrical connection can be made as well.
There are two sets of conducting pins in aforementioned female connector, so that the cost is much higher than the cost of a prior female connector. However, to use a general male connector to connect with the female connector, only one set of conducting pins in the female connector are electrically connected, and therefore the female connector can only achieve a transmission rate that is the same as the prior female connector, so that it does not fit an economic effect.